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For a sense of scale, that screw is 6-32. This is used for pulling needles off of dial indicators and dial calipers when they need repair (or just to confound you're associates ). I made this two years ago or so to repair my dial calipers.

Making dedicated arbours for oft-used drills makes a lot of sense. But, unless you have a lever operated tailstock, you still need to wind the tailstock barrel back a long way to eject the arbour and have enough clearance to get the arbour out of the tailstock taper.

The drills that you show are all small, and won't put a lot of torque on the morse taper section of the taper.

To save winding the barrel back & forth, how about halving the length of the Morse taper section of the arbours (just keep the large end of the taper, saw the smaller half off). It should leave enough length to centre, align and drive the arbour - it'll still be longer than the average ER collet.

This'll let you remove the arbour with less retraction of the barrel. Snag is, of course, it then won't self eject.

Get around this by machining a ring into the arbour just in front of the front face of the barrel. Make a fork with 2 pins that slips into the ring and lever against the front face of the barrel to pop the arbour out.

Making dedicated arbours for oft-used drills makes a lot of sense. But, unless you have a lever operated tailstock, you still need to wind the tailstock barrel back a long way to eject the arbour and have enough clearance to get the arbour out of the tailstock taper.

Ian

No you are missing the point, its so you don't HAVE to wind right out. Look at the first pic and the last pic. The extended one will release within 1" the first one, like most people make need to rewind 3" to release.